Re: Expectation

What is that way?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Without the labels:

This is in the correct form which will be explained as we do larger problems. Anyway, you now throw away all rows that have a 1 and any rows below that. Then you throw away any columns with a 1 and all columns to the right of that one. You get:

As problems get bigger this method will look better and better.

In mathematics, you don't understand things. You just get used to them.

I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

Re: Expectation

Well, let's try it on another problem. Got any?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Is the answer 16?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Maybe 4?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

I got all that but wasn't sure what to do with the resulting column vector...

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

What?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Hi bobbym

How'd you get that equation?

What have you been busy with? The elections?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

You are actually gonna vote?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Btw, I found a better Markov chain for the problem:

(1/2 , 1/2 , 0)(1/2 , 0 , 1/2)( 0 , 0 , 1 )

With states: empty string, 'H' and 'HH'. These string keep record of what we had till now. If we didn't throw the coin or the last throw was a tail then we have the state string to be an empty string. If the last throw was a head and the state string before the throw was empty, then the new string is 'H'. And finally, if last state string is 'H' and we get another head, then the new state string is 'HH' and this is the absorbing state. When we apply the method you have there, we will get the column vector (6,4) which means that we can get to HH in 6 steps from an empty string and 4 steps from one H. So the answer is 6.

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

No I didn't. Btw, the formula seems kinda intuitive when compared to 1/(1-x) for summing the geometric series...

A new problem would be nice...

Yes, I'm surprised that you vote. Do you just cancel the ballot?

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Oh, that one! Yes, I am curious as to how you got it.

I am surprised because I have no idea who you would vote for...

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Expectation

Hmmm, most of the time we for against something, not for something. Of course it does not matter but, have you read "The Sea Wolf," by Jack London?

This is what I have in my notes:

Let E denote the expected number of tosses before you get two heads in a row. If your first toss is a tails, then the expected number of total tosses before two heads is E + 1. If your first toss is a head and your second toss is a tail, then the expected number is E + 2. If you toss two heads, then the number of tosses is 2. These events occur with probability 1/2, 1/4, and 1/4, respectively.

In mathematics, you don't understand things. You just get used to them.

I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

Re: Expectation

Ahhhh... I get it. Thank you for the formula.

No, I haven't read it.

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.